The 9 mistakes people make when buying, ordering, and drinking coffee — and what to do instead

• Business Insider spoke to Will Corby, Head of Coffee at Pact, to find out what bad habits we're keeping.
• He said people should treat coffee like vegetables and bread rather than a long-term product.
• He also explained why cheap instant coffee should be a red flag.

Whether it's choosing the wrong glass for your wine or abiding by old-school whisky rules, we make mistakes every day when it comes to how we eat and drink.

And buying and making coffee is no exception.

To find out what we're doing wrong when we buy, order, and drink it, Business Insider spoke to Will Corby, head of coffee at Pact Coffee, a London startup that delivers freshly roasted and ground coffee by post.

Corby has been working in the coffee industry for 12 years, has won and judged global barista awards, ran his own coffee shops, and also has experience roasting.

"For the past 12 years, I've specialised in the absolute pinnacle of coffee quality and optimising the process of growing it, shipping it, importing it, brewing it," he said. 

He's also been a head judge — appointed by the Colombian government — for the Colombian National Quality Competition for the past two years.

Now at Pact Coffee, he works on relationships with coffee founders to "develop practices, and increase quality and production in a sustainable manner," he said.

"We want to show the coffee in the best light we can, brew the coffee in the best possible way, [and] provide it to [people] in a way that makes it easy."

However, he said there's a lot of steps that go into making sure people have a good cup of coffee every day — and there are plenty of things you can do to make sure you're getting the most out of your java.

SEE ALSO: The biggest mistake people make when drinking wine is choosing the wrong glass — here's exactly how to drink Bordeaux, sauvignon blanc, chardonnay, and pinot noir

SEE ALSO: The 3 mistakes people make when buying, ordering, and drinking whisky — and what to do instead

1. Not buying it fresh like you would vegetables or bread...

"If you walk into a supermarket in the UK, coffee is treated like a dried fruit," Cory said. "You find it in an aisle with cereal, dried peas, long-life things."

However, he explained, coffee isn’t really a long-life product.

"One of the key things to explore is to drink your coffee really fresh," he said. "Think about it like fresh bread or vegetables."

One of the ways to do this is through a service like Pact, which sends out the coffee the day after it's been roasted, or from a local coffee shop or roaster.

2. ...Then keeping it for longer than a month

Coffee in the UK tends to be sold in 250g bags, according to Corby, which typically makes 13, 14, or 15 cups of coffee.

"That's about two-week supply if you drink it every day," he said, the ideal timeframe.

"You could be drinking it up to a month after it's been ground, but you’ll notice a drop off in the quality," he said. "After a month, it will begin to taste stale."

He added that every time you open and close the bag, you’re "allowing the aromatics to escape," meaning your coffee is losing its flavour.

3. Not making sure your grind size is consistent

You can usually buy whole beans or ground coffee suited for a cafetiere, drip, or a stove-top.

While this means you can successfully brew coffee in any of these methods, he said getting a consistent grind size is the real way to get a "really good brew" out of any method.

"Relatively small particles are going to over-extract, and make coffee taste more bitter than it should," he said.

Meanwhile, he added that large particles "add a [taste] that feels like acidity, which isn’t very pleasant."

A "mish-mash" of both will provide "an astringent flavour," according to Corby.

"You need to buy coffee that is ground quite specifically for the brew method you’re going to use to do it," he said.  "Once you have particles your own size, brew the coffee."